One frequently overlooked tech story from the Detroit show — other than the Jeep waterfall — was Ford's HySeries fuel-cell hybrid system, which powered the company's Airstream van concept. Rather than calling on the cell to power the all-EV car's electric motor directly, like most hydrogen vehicles, this system uses it only to top off the lithium-ion batteries that provide juice. Ford's already ported the hybrid drive, which includes a plug-in function, to an Edge crossover, which showed up on the streets of DC ahead of the city's auto show this week. As these shots indicate, local pols likely got to see where went the Department of Energy grant, with which Ford developed it.